1. Technical Field
The present application relates to a cutting insert made of cemented carbide having at least one recess for insertion therein of a cutting body consisting of a cutting material different from cemented carbide to form a firm connection, the cutting body having formed a cutting edge thereon.
2. Background Information
Cutting inserts of this type are known from U.S. Pat. Nos. 3,369,283 and 4,201,501 and from EP-B1-0 431 009, for example.
These prior cutting inserts consist of a cemented carbide based on tungsten carbide, the binder metal for the hard component being cobalt, nickel and/or iron in most cases, and the cutting body inserted in a recess of the cutting insert is made of a polycrystalline material, such as, e.g. diamond or cubic boron nitride. The polycrystalline material is bonded into the recess of the cutting insert with the aid of a suitable adhesive or is brazed into it. Suitable adhesives and brazing materials are commercially available.
In addition, cutting inserts have long been known which are made either of cemented carbide only or of a ceramic cutting material only.
While ceramic cutting inserts are basically more suitably used for high-temperature applications, i.e. for metal cutting of workpieces in the high-speed range, than cemented carbide cutting inserts, the lower transverse rupture strength of the ceramic cutting inserts becomes noticeable increasingly more negatively as the dimensions of the cutting inserts become smaller. For this reason it had so far not been possible to manufacture tools from a high-temperature resistant ceramic material which have a very small cutoff width or a very small radius for copy-turning in the high-speed range. On the other hand, it had so far not been possible to manufacture useful indexable inserts made of solid cemented carbide and having very small dimensions and simultaneously highly complex shapes.